[LeetCode] 53. Maximum Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [-2,1,-3,4,-1,2,1,-5,4],

the contiguous subarray [4,-1,2,1] has the largest sum = 6.

/*
* dp[i]表示以nums[i - 1]元素结尾的最大子数组
* 动态转移方程:
* dp[i] = dp[i - 1] > 0 ?
*                  dp[i - 1] + nums[i - 1] : nums[i - 1];
*/
class Solution {
public:
int maxSubArray(vector<int>& nums) {
const int n = nums.size();
vector<int> dp(n + 1);

dp[0] = -1;
int maxsum = INT_MIN;
for (int i = 1; i <= n; i++) {
dp[i] = dp[i - 1] > 0 ?
dp[i - 1] + nums[i - 1] : nums[i - 1];
maxsum = max(maxsum, dp[i]);
}

return maxsum;
}
};